It is described that the dithiocarbonimide compounds shown by the formula (I): ##STR3## (wherein R.sub.2 and R.sub.3 are the same or different, and represent a hydrogen atom, C.sub.1 to C.sub.6 alkyl group, halogen atom, C.sub.1 to C.sub.6 alkoxy group, C.sub.1 to C.sub.6 haloalkyl group, C.sub.1 to C.sub.6 haloalkoxy group, or R.sub.2 and R.sub.3 form a methylenedioxy group optionally substituted by fluorine atom(s) together. Z represents a CH group or nitrogen atom) have an excellent plant disease controlling activity in U.S. Pat. No. 5,563,159. The said Patent specification shows the method for producing the said dithiocarbonimide compounds by using the benzyl bromide derivative of the formula (II): ##STR4## as an intermediate.
EP-254,426-A and EP-398,692-A show the method for producing benzyl bromide derivative of the formula (II) by reacting 2-methylphenylacetic acid derivative of the formula (III): ##STR5## with N-bromosuccinimide(NBS). Furthermore, U.S. Pat. No. 5,047,408 shows the method for producing the benzyl bromide derivative of the formula (II) by reacting 2-methylphenylacetic acid derivative of the formula (III) with bromine under mercury lamp irradiation. However, the bromination process using NBS is not practical in industry and the reaction of bromine under mercury lump irradiation needs a photo-reaction facility. Therefore, it is desired to develop a method for producing the benzyl bromide derivative of the formula (II) that is advantageous in industry.